Hi Pengcheng:

I tried the violation below but I don't get
an error message. Please can you check.

-- Karl

A = B.
B = C.
C = D.
D = .

Main = <s> String.



Main {
  public static void main(String args[]) throws Exception {{
    A a = A.parse(System.in);
    D d1 = a.get_b().get_c().get_d();
    System.out.println("done");
  }}
}